35results about How to "Improve error precision" patented technology

The invention discloses a student comprehensive quality evaluation method based on a genetic algorithm optimization BP neural network. The method comprises following steps: S1. constructing sample data in a manner of acquiring sample data of all quality indexes of a student, wherein the sample data servers as training samples of the BP neural network; S2. determining a network topology structure in a manner of determining the number of BP neural network hidden layers and the number of nerve cells in each layer and initializing weight thresholds of the neural network; S3. optimizing weight thresholds in a manner of optimizing the weight thresholds of the BP neural network through a genetic algorithm; S4. training and testing in a manner of training the BP neural network and performing tests by the use of data which is not trained; and S5. evaluating the comprehensive quality of the student in a manner of inputting the data of all the quality indexes of the student to the trained BP neural network so as to evaluate the comprehensive quality of the student. By employing the method, the efficiency and accuracy of the student comprehensive quality evaluation can be improved.

The invention relates to a PDF modeling method for the output fiber form of the stochastic dynamic system of a high-consistency disc refiner in the pulping process based on random distribution theory and wavelet neural network, and belongs to the field of modeling and control of the stochastic dynamic system of high-consistency refining pulping in the pulping and papermaking process . The method uses the local time domain and frequency domain characteristics of the wavelet neural network intelligent modeling method and the powerful nonlinear function approximation ability, and combines the random distribution B-spline basis function approximation probability density function theory to establish the output of the high consistency refining system. A nonlinear dynamic model between the fiber morphology distribution PDF and the main input variables of the disc refiner. Compared with the previous modeling method, the method of the invention is more intuitive and stable, has high error precision, and avoids the drawbacks of strong hypothesis and poor universality of the mechanism model. At the same time, the prediction of the output PDF of the high-consistency refining system is realized, which lays a theoretical foundation and reference value for the online real-time soft measurement of the output pulp fiber form parameters of the high-consistency refiner, and also provides a basis for the tracking control and operation optimization of the output fiber form distribution PDF. Model basis.

The invention discloses an artificial core analysis and preparation method for displacement experiments based on experiments and mathematical algorithms combining qualitative and quantitative methods. The physical parameters of the artificial core are taken as the target parameters for the preparation of the artificial core; the influencing factors of the physical parameters of the artificial core are determined; several combined experiment schemes are formulated, and the artificial core is made according to each combined experimental scheme, and the physical parameters of the artificial core are measured after the preparation is completed; Based on the preparation condition parameters of the experimental plan, based on the gray correlation analysis method, the correlation degree between each influencing factor and each target parameter is determined; according to the ranking of the correlation degree between each influencing factor and the target parameter, the larger influencing parameter and the smaller influencing parameter are determined ;Based on the statistical analysis results of the gray correlation method and BP neural network theory, a particle size ratio prediction mathematical model is established; the ratio prediction results are calculated through the particle size ratio prediction mathematical model, and this is used as a reference to provide data support for making artificial cores.

The invention relates to a method for improving the measurement accuracy of an intelligent electric meter. The purpose is to provide a method for improving the measurement accuracy of the smart electric meter, which has a wide measurement range and low cost. Solution: Divide the working temperature range of the meter from ‑40°C to +70°C into N1...Nm intervals, calculate the voltage compensation gain value Ugain and the voltage compensation gain value Igain according to the following formula, and update them in real time, Ugain=Ugb±(Tx‑Tn) *U; Igain=Igb±(Tx-Tn)*I. The invention is used in the smart electric meter industry.

The invention provides a heat conductivity coefficient calculation method applicable to saturated sandy frozen soil. The method comprises the following steps: converting volume of soil skeleton in saturated sandy frozen soil of which dry density is calculated to be rho d; determining the content of unfrozen water in the saturated sandy frozen soil with the dry density rho d according to an unfrozen water test; determining the volume content of an ice body in the saturated sandy frozen soil; respectively calculating volume ratios of the soil skeleton, the unfrozen water and the ice body accounting for the saturated sandy frozen soil in the saturated sandy frozen soil; and calculating the heat conductivity coefficient lambda of the saturated sandy frozen soil. The method disclosed by the invention has the effects that the method has the characteristics of intuitiveness, convenient calculation and the like and provides a convenient means for calculating the heat conductivity coefficient of the saturated sandy frozen soil. According to the calculation and measurement contrast, the prediction error of the calculation method on the heat conductivity coefficient of the sandy frozen soil is within 4.31%. Due to the increase of the error precision, the calculation precision of the heat conductivity coefficient of the frozen soil can be improved to the greatest degree, and convenience is provided for temperature field prediction in frozen soil engineering.

A bus travel time prediction method based on sparse GPS data, the invention relates to a bus travel time prediction method based on sparse GPS data. The purpose of the present invention is to solve the problem of low credibility of bus travel time prediction due to the sparse nature of bus data at the present stage. The specific process of a bus travel time prediction method based on sparse GPS data is as follows: Step 1. After receiving the original GPS data uploaded by the bus vehicle, the original GPS data of the bus is normalized and preprocessed, and the normalized preprocessed Integrate the data into a two-dimensional space-time velocity matrix; Step 2: Construct a generative confrontation network based on the traffic flow prior rules to generate the actual traffic status of the bus line; Step 3: Based on the model-free adaptive driving method, online prediction of the bus schedule time. The invention is used in the technical field of public transportation information processing.

The invention provides an unfrozen-water content calculating method based on a frozen soil heat-conduction coefficient. The method comprises the following steps: determining a heat conduction coefficient lambda of a saturated frozen soil sample with dry density of Rhod under negative temperature, drying the soil sample and determining a heat conduction coefficient ks of the soil sample under negative temperature; converting the dry density as Rhod and proportion of soil skeleton in frozen soil in bulk volume as Vs; calculating the volume ratio of unfrozen-water in frozen soil; calculating the proportion of the soil skeleton and the ice body in the frozen soil; and calculating the unfrozen-water content Wu in the frozen soil. The method has characteristics of direct viewing and convenient calculating, and provides means for calculating the unfrozen-water content. By comparing calculating value and actual measurement value, the prediction error provided by the calculating method is within 12.2%. The precision increase can greatly increase the calculating precision of the unfrozen-water content, and provides the calculating convenience of a temperature field in frozen soil engineering.

The invention discloses a bipolar anti-irradiation 5-A low-voltage wideband linear voltage regulator. A voltage signal output and subjected to voltage dividing by the linear voltage regulator is compared with the 0.7-V high-precision reference voltage and amplified through a wideband two-level differential amplifier; a buffer processes the signal compared and amplified by the operational amplifier, and thus the output signal has the current driving capacity; and an output power module with a fast access is controlled to achieve 5-A low-voltage wideband voltage stabilizing output. A zero-pointcompensation and Miller compensation method is adopted to design an amplification structure, output impedance of a dominant pole is significantly reduced through a bias circuit of an emission structure, the bandwidth of the operational amplifier (with the unit gain bandwidth product being larger than 20 MHz) is increased, specifically, through a buffer structure with the emission structure and a Darlington output structure, the bandwidths of all nodes of an output circuit and a buffer circuit are pushed to high frequency, static working current of the circuits is reduced, and thus the linear voltage regulator has the working bandwidth larger than 15 MHz, and the characteristic of fast loading of the transient response.

The invention provides an unmanned vehicle-side longitudinal coupling tracking control method based on a rapid terminal sliding mode principle. The method comprises the following steps: 1) selecting an input parameter and an output parameter of an unmanned vehicle-side longitudinal coupling tracking controller; 2) defining a tracking control error and a state equation; 3) using the tracking control error as a state variable and establishing a rapid terminal sliding mode; 4) taking a rapid terminal tendency rate as a sliding mode tendency rate of the tracking control; 5) according to a vehicle dynamics model and the above content, deriving a coupling relation between an expected driving force or a braking force and an expected side force; 6) calculating an expected front-wheel turning angle; 7) according to positive or negative of obtained reverse longitudinal force model output, determining whether an expected throttle percentage or an expected braking torque should be calculated currently; 8) calculating the expected throttle percentage or the braking torque. From a simulation result, by using the method in the invention, error precision of position tracking control is increased and good error precision of speed tracking control is possessed.

The invention belongs to the technical field of a maser and discloses a Q-switching device and method for a maser working in the room temperature earth magnetic field. According to the method, a control panel, a voice coil motor and a laser are started, the motor is driven through a control panel driving circuit, the frequency and range of the voice coil motor moving back and forth are set, a limit switch is set to prevent a resonant frequency tuning disk from bumping a resonant chamber during movement, a grating scale sensor QH-200 outputs a signal with specific waveform to the control panel,the initial position is set, a signal is outputted by the control panel to the laser, a power peak of the output microwave from a coupling ring is observed by an oscilloscope, after debugging is completed, setting of the initial position is changed, the situation of the i-th work is observed, the power peak of the output microwave is recorded, the Q-switching position is determined through continuously narrowing the range, the final position is finally calibrated, and Q-switching of the maser is completed. The method is advantaged in that problems of relatively low output power and efficiencyexisting in the maser working in the room temperature earth magnetic field can be effectively solved.

The invention discloses a pouring trolley control system for railway track bed solidification equipment. A detection switch group is connected to a control module. The control module is respectively connected to a touch screen, an actuator, a position control module and a servo driver, and the position control module is connected to a digital input / output module. , the servo driver is connected with the servo motor; the upper switch of the lifting cylinder and the lower switch of the lifting cylinder are installed at both ends of the cylinder, the reference point proximity switch detection body is set on the side of the trolley frame near the electric control box end of the pouring trolley, and the detection body of the negative limit switch is at the The other side of the trolley frame near the end of the electric control box of the pouring trolley; the positive limit switch detection body and the reference point proximity switch detection body are on the same side of the trolley frame; the cylinder up valve and cylinder down valve are set on the tank chain connected to the pouring head The end, the cylinder ascending speed regulating valve and the cylinder descending speed regulating valve are installed at the upper and lower ends of the cylinder respectively. It can realize the automatic and accurate positioning of the pouring point, and the pouring volume and flow rate of the pouring point can be set according to the actual construction situation.

The invention discloses a control system for a pouring dolly of a railway ballast curing device. A detection switching group is connected with a control module. A control module is connected with a touch screen, an execution element, a motion control module, and a servo driver. The motion control module is connected with a digital quantity input / output module. The servo driver is connected with a servo motor. A lifting cylinder up-side switch and a lifting cylinder down-side switch are respectively installed on two ends of a cylinder. A reference point proximity switch detection body is arranged on a side of a dolly frame, close to the end of a pouring dolly electric cabinet. A negative capacity switch detection body is on the other side of the dolly frame, close to the end of the pouring dolly electric cabinet. A positive capacity switch detection body and a reference point proximity switch detection body are on the same side of the dolly frame. A cylinder rising valve and a cylinder lowering valve are arranged on the tip of a tank chain connected with a pouring head. A cylinder rising governing valve and a cylinder lowering governing valve are respectively installed on the upper end and the lower end of the cylinder. The system can realize automatic accurate positioning of pouring points, and pouring amount and flow velocity of the pouring points can be set according to practical construction conditions.

The invention provides a movable platform capable of realizing six-degree-of-freedom posture adjustment. The movable platform capable of realizing six-degree-of-freedom posture adjustment comprises a vehicle body, a walking device and a posture adjustment mechanism; the vehicle body comprises a vehicle frame, a walking mechanism arranged at the bottom of the vehicle frame and supporting wheels arranged at four corners of the vehicle frame, and the vehicle frame serves as an upper platform of the posture adjustment mechanism at the same time; the posture adjustment mechanism comprises a lower platform and six UPS driving branches; the lower platform, the six UPS driving branches and the vehicle frame jointly form the posture adjustment mechanism; a driving motor drives a lead screw to linearly move, and a lead screw nut is driven to move; then the lead screw nut drives four branches of a quadrilateral rod set connected to the two sides of the lead screw nut to move; and therefore, a U pair and an S pair connected to the first branch and the fourth branch are driven to move, the vehicle frame and the lower platform are made to move, and when the lower platform falls on the ground, the posture of the vehicle frame continues to be adjusted. The movable platform capable of realizing six-degree-of-freedom posture adjustment is compact in overall structure and low in height, and the high-precision six-degree-of-freedom posture adjustment platform for large-scale multi-degree-of-freedom satellite assembling can be achieved.